O.S. has now introduced new Glow Plugs that are more suited to rigors of R/C car racing, they have increased durability (longer life span of plug). More reliable idle characteristics. Smoother transitions from higher to lower RPM. Designed for constant "ON/OFF" throttle operations. This plug is suitable for 1/10 and 1/8 scale off-road racing. It has a slightly lower heat range than the O.S. This product includes one #10 (formerly A5) glow plug with brass gasket.